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//  Copyright Microsoft Corporation
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namespace DurableTask.Core.History
{
    using DurableTask.Core.Tracing;
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Runtime.Serialization;

    /// <summary>
    /// A history event for orchestration execution starting
    /// </summary>
    [DataContract]
    public class ExecutionStartedEvent : HistoryEvent, ISupportsDurableTraceContext
    {
        /// <summary>
        /// The orchestration instance for this event
        /// </summary>
        [DataMember] public OrchestrationInstance OrchestrationInstance;

        /// <summary>
        /// Creates a new ExecutionStartedEvent with the supplied parameters
        /// </summary>
        /// <param name="eventId">The event id of the history event</param>
        /// <param name="input">The serialized orchestration input </param>
        public ExecutionStartedEvent(int eventId, string input)
            : base(eventId)
        {
            Input = input;
        }

        /// <summary>
        /// Creates a new ExecutionStartedEvent
        /// </summary>
        internal ExecutionStartedEvent()
        {
        }

        /// <summary>
        /// Creates a new ExecutionStartedEvent with the same fields as <paramref name="other"/>.
        /// A deep copy is performed on all non-base class fields.
        /// </summary>
        internal ExecutionStartedEvent(ExecutionStartedEvent other)
        {
            // Copy base class fields
            EventId = other.EventId;
            Timestamp = other.Timestamp;
            ExtensionData = other.ExtensionData;
            IsPlayed = other.IsPlayed;

            // Deep copy all other fields
            OrchestrationInstance = other.OrchestrationInstance?.Clone();
            ParentInstance = other.ParentInstance?.Clone();
            ParentTraceContext = other.ParentTraceContext?.Clone();
            Input = other.Input;
            Name = other.Name;
            Version = other.Version;
            Tags = other.Tags != null ? new Dictionary<string, string>(other.Tags) : null;
            Correlation = other.Correlation;
            ScheduledStartTime = other.ScheduledStartTime;
            Generation = other.Generation;
        }

        /// <summary>
        /// Gets the event type
        /// </summary>
        public override EventType EventType => EventType.ExecutionStarted;

        /// <summary>
        /// Gets or sets the parent instance of the event 
        /// </summary>
        [DataMember]
        public ParentInstance ParentInstance { get; set; }

        /// <summary>
        /// Gets or sets the orchestration name
        /// </summary>
        [DataMember]
        public string Name { get; set; }

        /// <summary>
        /// Gets or sets the orchestration version
        /// </summary>
        [DataMember]
        public string Version { get; set; }

        /// <summary>
        /// Gets or sets the serialized input to the orchestration
        /// </summary>
        [DataMember]
        public string Input { get; set; }

        /// <summary>
        /// Gets or sets a dictionary of tags of string, string
        /// </summary>
        [DataMember]
        public IDictionary<string, string> Tags { get; set; }

        // TODO: Make this property obsolete
        /// <summary>
        /// Gets or sets the serialized end-to-end correlation state.
        /// </summary>
        [DataMember]
        public string Correlation { get; set; }

        /// <summary>
        /// The W3C trace context associated with this event.
        /// </summary>
        [DataMember]
        public DistributedTraceContext ParentTraceContext { get; set; }

        /// <summary>
        /// Gets or sets date to start the orchestration
        /// </summary>
        [DataMember]
        public DateTime? ScheduledStartTime { get; set; }

        /// <summary>
        /// Gets or sets the generation of the orchestration
        /// </summary>
        [DataMember]
        public int? Generation { get; set; }

        // Used for Continue-as-New scenarios
        internal void SetParentTraceContext(ExecutionStartedEvent parent)
        {
            this.ParentTraceContext = parent.ParentTraceContext;
        }
    }
}